All questions of Environmental Issues for Civil Engineering (CE) Exam

Reducing Global Warming

Introduction:
Scientists have suggested the use of cirrus cloud thinning technique and the injection of Sulphate aerosol into the stratosphere as a means to reduce global warming. These techniques aim to mitigate the adverse effects of climate change by altering the Earth's energy balance.

Global Warming:
Global warming refers to the long-term increase in the Earth's average surface temperature due to the accumulation of greenhouse gases in the atmosphere. This increase in temperature is primarily caused by human activities such as the burning of fossil fuels, deforestation, and industrial processes.

Cirrus Cloud Thinning Technique:
Cirrus clouds are high-altitude clouds composed of ice crystals. They have a warming effect on the Earth's surface as they trap outgoing longwave radiation. By thinning these clouds, scientists aim to reduce their warming effect and allow more longwave radiation to escape into space.

Injection of Sulphate Aerosol into Stratosphere:
Sulphate aerosols, when injected into the stratosphere, can reflect a portion of the incoming solar radiation back into space. This reflection of sunlight can have a cooling effect on the Earth's surface, counteracting the warming caused by greenhouse gases.

Scientific Rationale:
The cirrus cloud thinning technique and the injection of Sulphate aerosol into the stratosphere are proposed as geoengineering solutions to reduce global warming. These techniques aim to artificially modify the Earth's climate system to offset the warming caused by greenhouse gas emissions.

Challenges and Risks:
While these techniques may have the potential to reduce global warming, they also come with significant challenges and risks. The long-term impacts of manipulating the Earth's climate system are still not fully understood, and there is a potential for unintended consequences. Additionally, implementing these techniques on a global scale would require significant resources and international cooperation.

Conclusion:
In conclusion, some scientists suggest the use of cirrus cloud thinning technique and the injection of Sulphate aerosol into the stratosphere as a means to reduce global warming. These techniques aim to alter the Earth's energy balance by reducing the warming effect of cirrus clouds and reflecting sunlight back into space. However, the implementation of these techniques comes with challenges and risks that need to be carefully evaluated before considering their widespread use.

The most common nutrients causing eutrophication are nitrogen N and phosphorus P. The main source of nitrogen pollutants is run-off from agricultural land, whereas most phosphorus pollution comes from households and industry, including phosphorus-based detergents.

The Environment Protection Act (EPA) was enacted in 1986 with the objective of providing the protection and improvement of the environment.

The Acidification of Oceans - A cause of concern

Introduction:
Ocean acidification is a phenomenon that results from the dissolution of carbon dioxide (CO2) in seawater. The increase in CO2 concentration in the atmosphere leads to an increase in the amount of CO2 that dissolves in seawater, causing a decrease in ocean pH.

Effects of ocean acidification:
Ocean acidification has numerous effects on marine ecosystems. Some of the significant effects are:

1. Adverse effect on calcareous phytoplankton:
Calcareous phytoplankton, such as coccolithophores, are tiny marine organisms that play a vital role in the ocean's food chain. They are an essential source of food for many marine organisms, including zooplankton, which, in turn, are food for larger animals. The acidification of seawater makes it difficult for these organisms to form their calcium carbonate shells. This leads to a decline in their population, which has a cascading effect on the entire marine ecosystem.

2. Adverse effect on coral reefs:
Coral reefs are one of the most biodiverse ecosystems on the planet. They are made up of tiny polyps that build calcium carbonate skeletons. The acidification of seawater makes it difficult for these polyps to build their skeletons, which can lead to the loss of coral reefs. Coral reefs provide habitat and shelter for a vast number of marine organisms, including fish and invertebrates. The loss of coral reefs can have a significant impact on the entire marine ecosystem.

3. Adverse effect on animals with phytoplanktonic larvae:
Many marine animals, such as oysters, clams, and sea urchins, have larvae that feed on phytoplankton. The acidification of seawater makes it difficult for these larvae to find food, which can lead to a decline in their population.

4. Adverse effect on cloud seeding and formation:
Clouds play a vital role in regulating the Earth's climate. They reflect sunlight back into space, which helps to cool the planet. The acidification of seawater can impact cloud seeding and formation, which can have a significant impact on the Earth's climate.

Conclusion:
In conclusion, ocean acidification is a growing concern for marine ecosystems. It has numerous adverse effects on marine organisms, including calcareous phytoplankton, coral reefs, and animals with phytoplanktonic larvae. It can also impact cloud seeding and formation, which can have a significant impact on the Earth's climate. It is essential to take steps to reduce CO2 emissions to slow down the process of ocean acidification.

Montreal Protocol is associated with the issue of control and phasing out of the use of ozone-depleting substances.

Background:
In the 1970s and 1980s, scientists discovered a hole in the ozone layer over Antarctica. The ozone layer, which absorbs harmful ultraviolet radiation from the sun, is important for protecting life on Earth. It was found that certain man-made chemicals, such as chlorofluorocarbons (CFCs), were responsible for the depletion of the ozone layer.

Montreal Protocol:
To address this issue, the international community came together to negotiate the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987. The aim of the protocol was to phase out the production and consumption of ozone-depleting substances.

Key Provisions:
- The protocol required participating countries to phase out the production and consumption of ozone-depleting substances, such as CFCs, halons, and methyl bromide.
- It established a timetable for the phase-out, with developed countries required to phase out production and consumption by 1996, and developing countries given longer timelines.
- The protocol also established a financial mechanism to support developing countries in their efforts to phase out ozone-depleting substances.

Impact:
The Montreal Protocol has been successful in reducing the production and consumption of ozone-depleting substances. As a result, the ozone layer is slowly recovering, and it is expected to fully recover by the middle of this century.

Conclusion:
The Montreal Protocol is an important international agreement that demonstrates the ability of the international community to come together to address global environmental issues.

Sources of Methane as a Greenhouse Gas

Methane is a potent greenhouse gas that contributes to global warming. Sources of methane include:

1) Rice fields
2) Coal mining
3) Domestic animals
4) Wetlands

Explanation:

1) Rice fields: Methane is produced in rice paddies due to the anaerobic conditions in the soil. When rice fields are flooded, organic matter in the soil breaks down and produces methane as a byproduct.

2) Coal mining: Methane is often found in coal seams and can be released during mining operations. This methane can escape into the atmosphere and contribute to global warming.

3) Domestic animals: Methane is produced during the digestive process of domestic animals, such as cows and sheep. This methane is released through belching and flatulence.

4) Wetlands: Wetlands are natural sources of methane due to the anaerobic conditions in the soil. When organic matter in the soil breaks down, methane is produced as a byproduct.

Conclusion:

All of the above sources are major contributors to methane emissions and therefore contribute to global warming. It is important to find ways to reduce methane emissions from these sources in order to mitigate the impacts of climate change.